Endogenous insulin-like growth factors regulate the proliferation of TSH-independent mutants derived from FRTL5 cells. |
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| Authors: | P Chieffi A Picascia R Stanzione G Villone D Tramontano |
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| Institution: | CEOS/CNR, Dipartimento di Biologia e Patologia Cellulare e Molecolare Luigi Califano, Università di Napoli Federico II Naples, Italy. |
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| Abstract: | TSH-independent mutant clones (M cells) derived from FRTL5 cells, proliferate vigorously in the absence of TSH. The growth of M cells is stimulated by IGF-I in a dose-dependent fashion, but it is not influenced by TSH. Sm1.2, an antibody against IGF-I cross-reacting with IGF-II, significantly decreases basal DNA synthesis in the M cells. Binding of 125I-IGF-I to M cells is significantly lower than that to FRTL5 cells. M cells produce in their culture medium IGF-like peptides which appear to influence their basal DNA synthesis and the availability of type I receptors to bind exogenous IGF-I. |
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